how can i create a profile here in tumblr?

Ermm by profile do you mean an about me section like I have on the left hand side of my page? It depends on theme - you need a theme which has an about me section already in built, and then you can just type whatever you want for your profile into that. There are probably more complex methods that I don’t understand like editing the html or something to put an about me section in, but I would recommend finding a theme with one already built in that you can just edit easily :)